More than 500,000 Systems Infected with Stantinko Malware

Stantinko malware may only have recently been detected, but it is far from a new malware variant. It has been in use for the past five years, yet has only recently been identified. During the past five years, Stantinko malware has spread to more than 500,000 devices and has been operating silently, adding infected systems to a large botnet, with the majority of infected machines in Russia and Ukraine.

The botnet has primarily been used to run a largescale adware operation. The malware installs the browser extensions Teddy Protection and The Safe Surfing, which appear to users to be legitimate apps that block malicious URLs. These apps are legitimate if downloaded via the Chrome Web Store, but they are not if they are installed by Stantinko. The Stantinko versions contain different code that is used for click fraud and ad injection.

ESET reports that additional plugins known to be installed by Stantinko malware include Brute-Force and Search Parser which are used for Joomla/WordPress brute force attacks and to anonlymously search for Joomla/WordPress sites. Remote Administrator is a fully functional back door and Facebook Bot can generate fake likes, create new accounts, or add friends on Facebook, virtually undetected.

While click fraud is the primary goal of the attackers, Stantinko malware can perform a wide range of functions. Since Stantinko includes a loader, enabling threat actors to send any code to an infected device via their C2 server and run the code.

ESET researchers say the malware uses Windows services to perform backdoor activities and brute force attacks on WordPress and Joomla websites. Once access is gained, the attackers sell on the login credentials to other cybercriminal groups, according to ESET. That’s not all. ESET says Stantinko malware could be used to perform any task on an infected host.

The malware and botnet have remained undetected for so long due to their ability to adapt to avoid being detected by anti-malware solutions. The malware also uses code encryption to avoid detection. Users would be unlikely to realize that anything untoward was happening on their machine. The tasks performed by the malware involve low CPU activity and do not slow an infected device considerably.

Infection is believed to occur through illegal file sharing, especially the downloading of pirated software. However, ESET notes that infection has occurred through fake torrent files that are actually executables.

Removal of the malware is not straightforward. The malware installs two Windows services, each of which is capable of reinstalling the other service if one is deleted. If for any reason that process fails, the attackers can reinstall those services via their C2 server.

The discovery of Stantinko malware highlights the danger of failing to prevent employees from accessing file sharing websites at work. The downloading of pirated material, even accessing torrents files, has potential to infect enterprise networks with malware. Even if anti-virus and anti-malware solutions have been deployed, there is no guarantee that malware will be detected.

Organizations can protect against these types of attacks by implementing a web filtering solution and blocking access to file sharing websites and torrents sites. If these sites cannot be accessed and pirated software downloads are blocked, infection can be prevented.